PhD project offered by the IMPRS-gBGC in Jan 2026

All shapes and sizes? Investigating tree morphological adjustments to a changing climate

Manon Sabot , Anke Hildebrandt , Christine Römermann , Sönke Zaehle , Christian Wirth

Project description

Trees exhibit extraordinary variation in architecture and size, shaped by trade-offs between resource acquisition, allocation, and mechanical stability. Morphological characteristics related to growth — leaf size, canopy structure, branching patterns, stem thickness, root architecture — greatly affect the productivity and functioning of vegetation, including its resilience to, for example, drought, and pests and pathogens. This, in turn, influences carbon and water cycles, surface energy fluxes, and feedback mechanisms within the climate system.

Yet, our understanding of how the tree morphological forms that prioritise resource acquisition (e.g., canopy and root architecture) vs. mechanical strength and defence (e.g., wood density and leaf thickness) emerge across environmental gradients, species, and individuals remains incomplete, and there is considerable uncertainty concerning future adjustments as the climate continues to change.

This project seeks to inform global change modelling efforts by unlocking new theoretical understanding on ‘optimal’ tree morphology in the face of climate variability and biotic attacks. The project will draw from data collected in an ongoing controlled greenhouse experiment (canopy and root architecture, pests), from the synthesis of large existing data bases (e.g., TALLO, TRY), and from modelling (e.g., plant optimality frameworks). The exact methods are not set in stone; rather, they will be jointly decided to suit the candidate’s more specific interests and skills.

Working group & planned collaborations

The PhD candidate will work in the Climate and Plant Ecophysiology group in the Biogeochemical Signals Department at the Max Planck Institute for Biogeochemistry. They will have the opportunity to collaborate with researchers from other groups of the MPI-BGC, from the Friedrich Schiller University Jena, as well as from other institutions, including overseas.

Your profile

We welcome applications from interested, curious, exploratory-minded students from any country who

Have a Master degree in ecology, biology, physics, physical geography, mathematics, atmospheric science, or disciplines related to environmental sciences
Do not shy away from mathematics, equations, and quantitative questions
Have some knowledge of plant manipulation experiments, physiological measurements, or scientific computing (e.g., high-level programming)
Have good oral and written communication skills in English

Experience working in a scientific greenhouse or a large-scale experiment will be advantageous, as well experience related to plant pests and pathogens.

The Max Planck Society (MPS) strives for gender equality and diversity. The MPS aims to increase the proportion of women in areas where they are underrepresented. Women are therefore explicitly encouraged to apply. We welcome applications from all fields. The MPS has set itself the goal of employing more severely disabled people. Applications from severely disabled persons are expressly encouraged.